High performance liquid chromatography (HPLC) is one of the most important analytical techniques. HPLC techniques are widely applied in chemistry, medical and pharmaceutical uses, environmental and food sciences, and many other fields.
Liquid chromatography employs a liquid as the carrier for analyte samples. The carrier or mobile phase passes through a stationary phase composed of particles packed in a tube or column. In a conventional HPLC, the particles can be about 7 um in size.
HPLC can be applied to analyte mixtures or species which can be dissolved in water, as well as polymers dissolved in organic solvents.
Recently, new HPLC-related techniques have been developed with improved means of detection. For example, Ultrahigh Pressure Liquid Chromatography (UPLC), Rapid Resolution Liquid Chromatography (RRLC), Ultrafast Liquid Chromatography (UFLC), Rapid Separation Liquid Chromatography (RSLC), and Fast Protein Liquid Chromatography (FPLC).
A drawback of conventional liquid chromatography methods and systems is the difficulty in combining the liquid chromatography apparatus with a mass spectrometer apparatus or other large, conventional analyte detection systems. A liquid chromatography apparatus having a large mass and size is difficult to use in combination with a mass spectrometer that is also typically large.
Further, in medical and health care settings, it would be desirable to have a small and efficient liquid chromatography apparatus so that certain measurements can be done on-site in a patient clinic, rather than being carried out in a larger facility such as a medical center or hospital.
Moreover, for environmental measurements that should be performed in the field or at remote locations such as a rainforest, a geological location such as a volcano, or in a spacecraft or extraterrestrial location, it can be required to have a small and efficient liquid chromatography apparatus. Such a device would allow detection of analytes, chemicals, contaminants or other species at their source.
Another drawback of conventional liquid chromatography methods and systems is the use of a photomultiplier as a light sensor. When a photomultiplier is used as a light sensor, a monochromator and mirrors are generally required to isolate wavelengths of light from the sample.
On the other hand, it is desirable to have a liquid chromatography apparatus that can simultaneously and efficiently detect a range of wavelengths of light.
A further drawback of conventional liquid chromatography methods and systems is in using screw-operated pump heads for liquid transport, which have large mass.
There is a continuing need for a liquid chromatography apparatus having a detector device that can measure a range of wavelengths of light simultaneously. There is also a need for a liquid chromatography apparatus that can provide efficient pumping with less mass. And there is a long standing need for efficient liquid chromatography methods and systems for use with other detection systems, as well as for making measurements in the field.